Design And Analysis Of A Robot For Out-of-pipe Inspection Of Marine Pipeline

Marine pipeline is the lifeline of offshore oil and gas fields.The robot can replace the diver to complete the real-time monitoring and data feedback of the state of offshore pipeline,which is helpful for staff to master the operation of offshore pipeline.In this paper,the overall scheme design,the design and verification of the main parts,the kinematics and mechanics analysis of the robot,the finite element analysis of the main structure and the design and research of the control system are mainly carried out.Thus,the independent research and development of the inspection robot for the pipeline is completed.In this paper,the overall scheme of the inspection robot outside the pipeline is designed.The overall structure and design parameters of the robot are given,and the underwater propeller and motor of the robot are selected.Finally,the obstacle-crossing and bend-crossing schemes of the robot are described.In this paper,the Design and Verification for the main parts of the robot has completed.The spring design and check of the obstacle-crossing device are completed,the material and structure parameters of the spring are determined,and the fatigue strength and static strength are checked.The design and verification of push rod for obstacle-crossing device are completed.The material and structural parameters of push rod are determined.The strength,stiffness and stability of pressure rod are checked.The design and checking of worm gear and worm are completed.The material and ruler structure parameters of worm gear and worm are determined.The bending fatigue strength of the tooth root of worm gear is checked.The transmission efficiency of worm gear and worm is calculated.The design and verification of the worm gear shaft are completed.The material and structural parameters of the worm gear shaft are determined.The strength of the shaft is checked according to the bending and torsion synthetic stress,and the fatigue strength of the shaft is checked accurately.The design and verification of the worm shaft are completed.The material and structural parameters of the worm shaft are determined.The strength of the worm shaft is checked according to the bending and torsion synthetic stress,and the stiffness is checked.The design of static seal of sealing chamber,dynamic seal of push rod and dynamic seal of turbine worm shaft for obstacle-crossing device were completed.In this paper,the kinematics and mechanics analysis for the inspection robot outside the pipeline has completed.The feasibility of the robot designed in this paper passing through the elbow is demonstrated.The buoyancy,resistance and friction force of the robot are analyzed,and the selection of underwater propeller and motor of the robot is verified,which ensures that the robot can meet the operation requirements.In this paper,the finite element analysis for the robot structure based on ANSYS has completed,which includes:the static analysis of claw plate above ground and under water,the static analysis of reducer and frame shell under water,the static analysis of connecting frame under water,the static analysis of connecting frame under water,the static analysis of electronic sealed silo under water and the modal analysis of the whole frame of the robot.A series of equivalent stress nephograms and total strain nephograms are obtained by static analysis,which verify the reliability of each structure at 200 m underwater depth.The natural frequencies and mode shapes of each order are obtained by modal analysis,which can provide data for avoiding resonance.In this paper,the design and research for the control system and algorithm of the robot has completed.CAN bus is chosen as the communication bus of its distributed control system,and the overall design of its distributed control system is carried out.The design and implementation of each subsystem of the ocean pipeline inspection robot are completed.The self-tuning PID control algorithm is selected as the motion control algorithm of the robot,and the related algorithms are studied.